1. Field of the Invention
Embodiments of the present disclosure generally relate to pressware stacking systems and methods for using the same.
2. Description of the Related Art
In a typical pressware product stacking system, a take-away table or conveyor transfers pressware products from a matched metal forming die to a stacking can. The products travel down the take-away table and then fall over the edge onto a stacking surface at the bottom of the stacking can or onto a partially completed stack. The system stacks the pressware products on top of each other until each stacking can contains the desired product count. Then the system transfers a completed stack to another conveyor that leads to packaging equipment.
Ideally, all the products in the system fall from the take-away table directly on top of the preceding products and nest perfectly to create a neatly stacked column of pressware products. In previous systems, many factors kept the products from stacking and nesting within each other, effectively leading to the introduction of “bouncers” or “shakers” to agitate the stack. In the past, the “shakers” have been either circular in shape having an eccentric bore or cam lobe shaped. Alternatively, previous systems provided agitation by actuating a small bar located under the pressware product stack with a linkage arm eccentrically mounted to a drive wheel. When used, these devices usually only contact the stack once per revolution. Additionally, some systems used low angled ramps separate from the agitation device to angle the stack during stacking.
While these previous agitation methods and stand alone angled ramp help the stacking process, efficiency has been limited. Efficiency is measured by the stacking system's ability to create a stack of products that do not require human intervention before packaging verses the total number of stacks produced during the same time period. Reasons for inefficient stacking vary. Frequently, products fall from the take-away table into the stacking can at random locations because of random ejection from the forming die. Products also may snag on surfaces and gaps along the system path or on the stack itself, resulting in improper nesting. Sometimes the “shakers” themselves cause stacking disruption, causing some products to bounce from the stack. Inefficient stacking may result in additional product cost from increased scrap from discarded product. Machine shutdowns from product jams caused by stacking can backups also affect press productivity. Additionally, excessive labor costs occur because of additional personnel requirements for machine and stack quality monitoring. Eliminating these issues may have a significant impact on reducing product cost, machine downtime, and labor expense.